1. Field of the Invention
This invention relates to cold rolled material manufacturing equipment and a cold rolling method.
2. Description of the Related Art
Cold tandem mill equipment having a plurality of cold rolling mills, i.e., 3 or more cold rolling mills, arranged therein, or continuous cold tandem mill equipment having a joining device and a strip storage device disposed on the entry side of the cold tandem mill equipment to perform continuous rolling without stopping rolling (such equipment will be referred to hereinafter as TCM equipment) is put to practical use as equipment for mass-producing cold rolled materials in an annual production volume of more than 1,200,000 tons to 1,500,000 tons. Commercial use is also made of continuous pickling cold tandem mill equipment (hereinafter referred to as PL-TCM equipment) in which pickling equipment for removing scale of a hot rolled strip is disposed between the joining device and the strip storage device in the TCM equipment to continuously carry out a series of steps ranging from a pickling step to a rolling step.
On the other hand, reversing cold rolling equipment (hereinafter referred to as RCM equipment), in which one cold rolling mill is disposed, and a strip winding/unwinding device for performing both of winding and unwinding of a strip is disposed on each of the entry side and the exit side of the cold rolling mill, so that the strip is rolled and reversely rolled between the winding/unwinding devices on the entry side and the exit side of the cold rolling mill until the strip reaches a desired strip thickness, finds practical use as rolling equipment for producing cold rolled materials in many types of steels and in annual production volumes as small as 300,000 tons.
To increase the annual production volume of the RCM equipment composed of one rolling mill as described above, a reversing small-sized rolling apparatus for cold rolling a strip-shaped rolling material (see Patent Document 1), for example, is known as equipment for producing cold rolled materials in an annual production volume of the order of 500,000 tons to 600,000 tons with the use of two rolling mills (hereinafter referred to as 2-stand reverse equipment).
Patent Document 1: Japanese Patent No. 3322984
Patent Document 2: JP-A-61-162203